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Commit dd9d598c authored by Xin Long's avatar Xin Long Committed by David S. Miller
Browse files

ip_gre: add the support for i/o_flags update via netlink 



Now ip_gre is using ip_tunnel_changelink to update it's properties, but
ip_tunnel_changelink in ip_tunnel doesn't update i/o_flags as a common
function.

o_flags updates would cause that tunnel->tun_hlen / hlen and dev->mtu /
needed_headroom need to be recalculated, and dev->(hw_)features need to
be updated as well.

Therefore, we can't just add the update into ip_tunnel_update called
in ip_tunnel_changelink, and it's also better not to touch ip_tunnel
codes.

This patch updates i/o_flags and calls ipgre_link_update to recalculate
these gre properties after ip_tunnel_changelink does the common update.

Note that since ipgre_link_update doesn't know the lower dev, it will
update gre->hlen, dev->mtu and dev->needed_headroom with the value of
'new tun_hlen - old tun_hlen'. In this way, we can avoid many redundant
codes, unlike ip6_gre.

Reported-by: default avatarJianlin Shi <jishi@redhat.com>
Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Acked-by: default avatarWilliam Tu <u9012063@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c7947e43

net/ipv4/ip_gre.c

+37 −2
Original line number Diff line number Diff line
@@ -773,6 +773,30 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, 
	return NETDEV_TX_OK;

}



static void ipgre_link_update(struct net_device *dev, bool set_mtu)

{

	struct ip_tunnel *tunnel = netdev_priv(dev);

	int len;



	len = tunnel->tun_hlen;

	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);

	len = tunnel->tun_hlen - len;

	tunnel->hlen = tunnel->hlen + len;



	dev->needed_headroom = dev->needed_headroom + len;

	if (set_mtu)

		dev->mtu = max_t(int, dev->mtu - len, 68);



	if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {

		if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||

		    tunnel->encap.type == TUNNEL_ENCAP_NONE) {

			dev->features |= NETIF_F_GSO_SOFTWARE;

			dev->hw_features |= NETIF_F_GSO_SOFTWARE;

		}

		dev->features |= NETIF_F_LLTX;

	}

}



static int ipgre_tunnel_ioctl(struct net_device *dev,

			      struct ifreq *ifr, int cmd)

{
@@ -1307,9 +1331,9 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 
			    struct netlink_ext_ack *extack)

{

	struct ip_tunnel *t = netdev_priv(dev);

	struct ip_tunnel_parm p;

	struct ip_tunnel_encap ipencap;

	__u32 fwmark = t->fwmark;

	struct ip_tunnel_parm p;

	int err;



	if (ipgre_netlink_encap_parms(data, &ipencap)) {
@@ -1322,7 +1346,18 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], 
	err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);

	if (err < 0)

		return err;

	return ip_tunnel_changelink(dev, tb, &p, fwmark);



	err = ip_tunnel_changelink(dev, tb, &p, fwmark);

	if (err < 0)

		return err;



	t->parms.i_flags = p.i_flags;

	t->parms.o_flags = p.o_flags;



	if (strcmp(dev->rtnl_link_ops->kind, "erspan"))

		ipgre_link_update(dev, !tb[IFLA_MTU]);



	return 0;

}



static size_t ipgre_get_size(const struct net_device *dev)